Dan...Go to NAPA they have a "O" ring assortment usually behind the counter. Bring the intake, match it up and you can purchase ...each for about $0.30. That is where I bought ours.
That's what I did Ron,(NAPA) I took A carb with me and they matched one up for me. All I need now is another mag. and bike. then I can replace the last STOLEN one. I have one more kit left.